A federal jury on Thursday found Randy Parks Sweeney guilty of sexual exploitation of a minor.
He was also ruled guilty of being a felon in possession of a weapon.
Sweeney faces sentencing on Jan. 5 from Judge Sandy Mattice.
Prosecutors said the 49-year-old Sweeney sent sexually explicit messages to a 13-year-old girl.
He claimed her 14-year-old boyfriend might have used his Facebook account to send the messages.